EP3597143B1 - Dental prosthesis - Google Patents

Description

The invention relates to a dental prosthesis according to the preamble of claim 1.

It has long been known to build prostheses, but also teeth, from several layers.

Examples are those from WO 90/13268 A1 and from the WO 91/07141 A1 known solutions called.

Based on these very old solutions, multilayer plastic elements have recently been proposed with the aid of CAD / CAM technology, which are intended to be used to create teeth and prostheses to provide teeth and the prosthesis base to provide a finished prosthesis. Due to the different requirements for the different materials, namely the flesh-colored denture base material on the one hand and the tooth-colored tooth material on the other hand, this proposal has not yet prevailed, even though it has already become known elsewhere to manufacture both teeth and a denture base from PMMA .

Furthermore, rapid prototyping processes have recently been proposed with the aim of providing both teeth and prosthesis bases made of plastic material - or possibly also of other materials. This development has not made any real progress either.

On the other hand, in view of the increasing life expectancy, there is an increasing demand for full and partial prostheses, with both full and partial prostheses being subsumed under the term prostheses for the sake of simplicity. This increasing demand is paired with increasing cost pressure, if only due to the anticipated significant increase in demand.

From the EP 3 064 170 A1 it is known to create the interface between the materials as a waveform extending in a radial manner. The wave shape can then immediately depict the chain line of the gingival margin.

This version has the advantage that, regardless of the size of the required dental arch, the gingival margin is always generated automatically, so that possible errors are automatically avoided in this respect.

Tests have shown that especially with small dental prostheses that are manufactured according to this solution, the chewing performance is perceived as unsatisfactory by the patient.

With this solution, patients with comparatively large dental arches sometimes find their front teeth somewhat misshapen.

In contrast, the invention is based on the object of creating a dental prosthesis according to the preamble of claim 1, which improves the known solutions both aesthetically and functionally, without any economic disadvantages.

This object is achieved according to the invention by claim 1. Advantageous further developments result from the subclaims.

According to the invention, it is provided first of all to provide a two-colored blank for a dental prosthesis. The area from which the dental arch will later be formed is tooth-colored, and the area from which the denture base will later be formed is flesh-colored.

On the other hand, in view of the increasing life expectancy, there is an increasing demand for full and partial prostheses, with both full and partial prostheses being subsumed under the term prostheses for the sake of simplicity. This increasing demand is paired with increasing cost pressure, if only due to the anticipated significant increase in demand.

From the EP 3 064 170 A1 and at the same time from the US 2018 071 063 A1 it is known to create the interface between the materials as a waveform extending in a radial manner. The wave shape can then immediately depict the chain line of the gingival margin.

This version has the advantage that, regardless of the size of the required dental arch, the gingival margin is always generated automatically, so that possible errors are automatically avoided in this respect.

Tests have shown that especially with small dental prostheses that are manufactured according to this solution, the chewing performance is perceived as unsatisfactory by the patient.

With this solution, patients with comparatively large dental arches sometimes find their front teeth somewhat misshapen.

In contrast, the invention is based on the object of creating a dental prosthesis according to the preamble of claim 1, which improves the known solutions both aesthetically and functionally, without any economic disadvantages.

This object is achieved according to the invention by claim 1. Advantageous further developments result from the subclaims.

According to the invention, it is provided first of all to provide a two-colored blank for a dental prosthesis. The area from which the dental arch will later be formed is tooth-colored and the area from which the denture base will later be formed is flesh-colored.

the dental arch is milled a little further radially outwards, i.e. in the vestibular direction, and with small dental arches it is milled further inwards, i.e. shifted orally.

Due to the parallelization according to the invention of the peaks and valleys of the interface for the area of the molars, a comparatively large occlusal surface is available according to the invention even with small dental arches.

It has been shown that it is precisely the oral tampers that are important for chewing efficiency, and it is precisely their shaping with good expression that is made possible by the interface according to the invention. Compared to the vestibular side, the same width in the mesial-distal direction is available for each tooth on the oral side, so that a massive tamped cusp can be easily accommodated there.

In addition, the front teeth are formative in terms of aesthetics. In the case of small dental arches for narrow face shapes and narrow mouths, according to the invention, a dental arch that is displaced radially inward, that is to say orally, can easily be milled, which results in correspondingly narrow front teeth.

Nevertheless, as explained above, the chewing function in the molar area is sufficient.

In an advantageous embodiment of the invention, in the area of the premolars and / or the canines, the parallelism of the grooves and ribs can be converted in the direction of the beam shape.

For example, the ones and twos may have radial grooves and ribs with a true center point of the beam. However, this is no longer properly hit by the three-rib. The rib in question is then less radial and more parallel to the adjacent double rib.

This also applies to the four-rib, which in turn has a course that is even closer to the parallelism.

The next following ribs, i.e. the fives, the sixes and the sevens, are completely parallel to each other.

In a further advantageous embodiment, it is provided that the partially radial, partially parallel course of the grooves and ribs, i.e. valleys and mountains, does not extend from the oral center to the vestibular outer edge, but only over a tooth formation area that has an oral-vestibular extension of, for example, 2 cm.

In this area it is planned that the dental arch is milled.

In this embodiment it is also sufficient to provide the tooth-colored material only in this area. The flesh-colored material is then provided throughout the rest of the blank.

The shaping area is in any case essentially U-shaped, that is, it runs like a U with quite wide legs.

The blank according to the invention can be disk-shaped, for example flat cylindrical with a protruding clamping edge and a diameter between 95 and 100 mm.

However, any other shape is also possible, for example also a tooth arch shape of the blank or a triangular shape.

The valleys of the interface are preferably adapted to the width of the tooth to be produced. In particular, the valley for the first molar can have the greatest valley width.

Both in the anterior tooth area and in the rest of the tooth area, the peaks and valleys within the shaping area have a congruent shape.

The peaks and / or the valleys can be connected at their peaks with a ridge line, which can run either straight or curved, for example also curved in an S-shape.

Provision is made to determine a suitable dental arch size via a scan of the patient's mouth or, if necessary, also via an impression, and based on this to determine the target size of the dental arch by defining the shaping line within the shaping area. The shaping line extends more orally for smaller target sizes and more vestibularly for larger target sizes.

To this extent, in a system that is not part of the invention, the point at which the dental arch is to be milled out is selected and determined in both horizontal directions.

In an advantageous embodiment, a system for producing a dental prosthesis based on a prosthesis blank is provided. The blank is produced in a suitable device, e.g. by injection molding. In this embodiment, the blanks have at least one reference marking on or with reference to the interface, real or virtual.

The boundary surface is thus marked directly or at least in the CAM / CAD data. The milling machine reads the reference marking and takes the limits up to which the tooth-colored and flesh-colored material is to be milled.

A storage device is provided in a further advantageous system for producing a dental prosthesis. This is arranged in a CAD / CAM device or the CAD / CAM device accesses the storage device,
The geometry of each blank, in particular also the extent of the interface in space, is stored there. A tooth library is also stored in the storage device. The CAD / CAM device or other computer makes a suggestion for setting up the teeth on the flesh-colored material, i.e. the later denture base.

However, this can still be changed by user intervention. It is also possible that the CAD / CAM device records the changes made by the user and takes them into account when creating new installation proposals. This is known as deep learning.

In an advantageous embodiment, an additional layer made of a material with different refractive properties, in particular due to different refractive indices of this material compared to the flesh-colored and the tooth-colored material, is arranged between the tooth-colored and the flesh-colored material. These properties are favored by the organic and / or inorganic components contained, which lead to a change in the transparency or opacity of the layer. They are preferably radically polymerizable, in particular thermally or light-initiated, and are processed thermoplastically together with the materials and introduced between the materials.

This creates an opaque layer, in particular made from an organic opaque, preferably from a light-curing opaque, formed on the Gernz surface between the materials. This prevents the flesh color of the base material from showing into the lighter tooth material and thus falsifying the natural appearance. Any grayish looking gingival margin is avoided and the chroma of the gingiva or tooth-colored material is not adversely affected.

Further advantages, details and features emerge from the following description of an exemplary embodiment of the invention with reference to the drawings.

Fig. 1

eine Unteransicht auf einen zu erstellenden Zahnbogen in einer erfindungsgemäßen Rohlingscheibe;

Fig. 2

eine Draufsicht auf den Zahnbogen gemäß Fig. 1, ebenfalls unter Darstellung des Prothesenrohlings;

Fig. 3

eine schematische perspektivische Ansicht eines erfindungsgemäßen Prothesenrohlings;

Fig. 4

eine schematische perspektivische Ansicht einer weiteren Ausführungsform eines erfindungsgemäßen Prothesenrohlings;

Fig. 5

eine schematische perspektivische Ansicht einer weiteren Ausführungsform eines erfindungsgemäßen Prothesenrohlings; und

Fig. 6

eine schematische perspektivische Ansicht einer weiteren Ausführungsform eines erfindungsgemäßen Prothesenrohlings.

Show it:

Fig. 1

a view from below of a dental arch to be created in a blank disk according to the invention;

Fig. 2

a plan view of the dental arch according to FIG Fig. 1 , also showing the prosthesis blank;

Fig. 3

a schematic perspective view of a prosthesis blank according to the invention;

Fig. 4

a schematic perspective view of a further embodiment of a prosthesis blank according to the invention;

Fig. 5

a schematic perspective view of a further embodiment of a prosthesis blank according to the invention; and

Fig. 6

a schematic perspective view of a further embodiment of a prosthesis blank according to the invention.

The in Fig. 1 The rolling 10 shown is essentially disk-shaped. The in Fig. 1 upper area is intended for the realization of a dental arch 11 and its underside Fig. 1 can be seen. The basal surfaces 13 of the individual teeth of the dental arch 11 can be seen.

The blank 10 consists of a disk of tooth-colored material and a disk of flesh-colored material which are connected to one another by gluing or in any suitable manner. The arrangement of the materials is better off Fig. 3 evident.

An interface 16 with an undulating course extends between the materials. The course is modeled on a human gingival margin.

Correspondingly, valleys 22 and mountains 24 alternate with one another, as is the case from Fig. 1 can be seen schematically.

The valleys 22, which correspond to grooves, are intended to receive teeth, and the peaks 24, which correspond to ribs, later form the interdental spaces.

The boundary surface 16 extends over the course of the dental arch 11 in an undulating manner. Viewed in the oral-vestibular direction, it has a special course.

In the area of the front teeth 33, the course is radial, starting from a ray center 36.

In contrast, the course of the wave crests and troughs in the oral-vestibular direction is non-radial in the remaining area. As far as the molars 26 are concerned, the peaks 24 and valleys 22 of adjacent teeth extend parallel to one another. The grooves 22 and ribs 24 can, however, also extend by a maximum of 10 degrees, in particular a maximum of 5 degrees, deviating from parallelism.

This also applies to the peaks and valleys of the premolars 28.

The rib 29 in the interdental space between the canine 31 and the first premolar 28 is parallel to the next distal rib. In its extension, however, it almost meets the beam center point 36. The valley 22, in which the canine tooth 31 is received, is widened outward in a ray-shaped manner, as is the valleys of the front teeth 33.

The area in which dental arches 11 can be created is limited in the oral vestibular direction. It is referred to as the shaping area 40.

An outwardly projecting clamping edge 50 is formed on the outer circumference of the blank 10. This is used in a manner known per se to accommodate the disk-shaped blank in the workpiece holder of a dental milling machine.

The disk formed by the blank 10 is basically circular. However, it has grooves 52 and 54 on a plane below the clamping edge 50. The grooves 52 and 54 are not diametrically opposed to each other, so that a rotation lock is ensured.

Out Fig. 2 is the blank disk according to Fig. 1 can be seen in the plan view of the dental arch 11. The same reference numerals indicate the same parts here as in the other figures.

The teeth 26, 28 and 31 can be seen with their occlusal surface 41, and it can be seen that, for example, a lot of space is available for the tamping cusp 43 of the first molar 26, even if the dental arch 11 is kept small, i.e. displaced orally .

Above the clamping edge 50, that is to say on the tooth side of the prosthesis, there is a different anti-rotation device than off Fig. 1 obviously provided. This has flats 58 and 60 which, like the grooves 52 and 54, are distributed asymmetrically.

In Fig. 3 a blank 10 is shown, which consists of a tooth-colored material 12 and a flesh-colored material 14. It is intended for the manufacture of a lower jaw dental prosthesis.

The blank 10 is essentially disk-shaped. An interface 16 between the tooth colored material 12 and the flesh colored material 14 is shown in FIG Fig. 3 evident. Has a specially shaped recess 18 in the flesh-colored material 14. Starting from the top 20 of the blank 10, the material 12 extends into the recess 18.

The tooth-colored material 14 of the blank 10 has a diameter or a width of more than 5 cm and in particular an essentially flat cylindrical shape with a diameter / height ratio of more than 2 to 1, preferably more than 3 to 1.

The flesh-colored and tooth-colored materials 14 and 12 are connected to one another, for example by gluing, by polymerizing and / or by one-piece production.

The recess essentially has the shape of a U with rather wide legs, that is, a dental arch shape. The interface 16 is formed there in a special way. It has a wave shape over the course of the U, corresponding to a gingival margin, i.e. essentially corresponding to a chain line.

The wave shape has alternating wave troughs 22 and wave peaks 24. The wave troughs are also grooves, and the wave crests are ribs.

The peaks of the wave peaks 24 and also the - downward facing - peaks of the wave troughs 22 each form a ridge line.

The ridge lines rise from distal 30 to mesial 32. The boundary surface 16 is therefore inclined in the blank 10 and is, as it were, higher at the front, that is to say in the area of the anterior, than at the rear.

This relates to the average profile of the interface 16, which is actually undulating as stated.

The angle of inclination or the inclination of the interface 16 averages 16 degrees here.

In the area of the front teeth or anterior, the wave crests and wave troughs 24 and 22 run radially from the oral to the vestibular direction. They extend radially outward from a ray center point 36.

On the other hand, they run parallel to one another in the area of the molars and premolars. The leg width of the U, and thus the width of the recess 18, is significantly more than is necessary for the shaping of teeth. The blank 10 is intended to be able to produce both large and small dental arches by milling teeth radially on the inside, radially in the center or radially on the outside, based on the center point 36.

In this respect, the entire width of the U is available as a shaping area 40 for shaping.

How out Fig. 3 As can be seen, the depression 18 is significantly deeper in the distal area 30 than in the mesial area 32. This results in a significantly greater height of the tooth-colored material 12 distally than mesially. As a result of this measure, the anterior tooth region 32 moves closer to the upper side 20 of the blank 10, and the undercuts required there can be milled quickly and precisely with short milling cutters.

Out Fig. 3 it can also be seen that the blank 10 has a circumferential clamping edge 50. The clamping edge 50 has the usual shape for dental disc blanks, and the disc-shaped blank 10 has a diameter between 95 and 100 mm.

Tooth-colored material 12 extends, receding, above the clamping edge 50. There grooves 52 and 54 are provided, which are arranged asymmetrically to one another, that is, not diametrically opposite one another, and serve as an anti-twist device.

In addition, flats 58 and 60 are formed on the underside 56 of the blank 10 in FIG. These are provided in the area of the material 14 and are also asymmetrical to one another. They are used for alternative clamping in newer milling machines so that they cannot rotate.

Out Fig. 4 a further embodiment of a blank 10 can be seen. Only the tooth-colored material 12 of the blank is shown, while the remaining parts are shown, for example, according to FIG Figure 3 extend and are formed.

At the in Fig. 3 On the side shown below, the occlusal plane 60 extends. Correspondingly, a tooth 41 is in Fig. 4 Drawn into the material 12 in such a way that its occlusal side faces the occlusal plane 60.

In contrast to the embodiments according to FIGS Figures 1 to 3 are in Fig. 4 the mountains, that is to say the ribs 24, are inclined in the vestibular-oral direction, while they are, for example, according to FIG Fig. 3 extend straight, i.e. parallel to the occlusal plane.

Orally, the ribs 24 are closer to the occlusion than vestibular.

The angle between the occlusal plane 60 and and the rib 24 can be adapted to the requirements within a wide range. For example, the angle can be 10 to 20 degrees, but also more.

The angle can also be different for the individual teeth or interdental spaces.

The mountains 24 correspond to the interdental spaces and the valleys 22 to the teeth.

In the Fig. 4 The slope shown relates both to the mountains 24 and to the valleys 22.

It has been shown that due to the inclination provided in this respect, a better adjustment is possible, especially in the case of large differences between dental arches.

Exemplary inclination angles of the mountains 24 are off Fig. 5 for the lower jaw and Fig. 6 six visible for the upper jaw. The angles of inclination specified there relate to a normal to the blank, which is disk-shaped.

In relation to the occlusal plane 60, the angles for the lower jaw are shown in FIG Fig. 5 between 10 degrees and 19 degrees and for the upper jaw between 15 degrees and 23 degrees.

It goes without saying that adaptations of the angles and also of the course of the ridge line, viewed over the dental arch, are possible over a wide range depending on requirements.

Claims (12)

1. A blank for the manufacture of a dental prosthesis, the blank being formed from a flesh-colored material (14) and a tooth-colored material (12), in particular each based on plastics material, which materials (12, 14) are joined to one another by bonding, by polymerization, by injection molding and/or by monobloc production, wherein the boundary surface (16) between the materials, as viewed in the course of the dental arch, is wave-shaped having mutually alternating grooves (22) and ribs (24) in the region of the anterior teeth (33) to be produced, and as viewed in the oral-vestibular direction, is radially formed, characterized in that the boundary surface (16), at least in the region of the molars (26) and in the region of the premolars (28) - as viewed in an oral-vestibular direction - has grooves (22) and ribs (24) parallel to each other, which form crests and troughs of the waveform.
2. The blank according to claim 1, characterized in that mutually parallel grooves (22) and ribs (24) are provided in the region of the molars (26) and in the region of the premolars (28), each one extending with a length of at least 2 cm from the oral oral to vestibular direction.
3. The blank according to claim 1 or 2, characterized in that the width of the troughs (22) is adapted to the respective width of the respective tooth to be produced and it is especially the trough (22) for the first molar (26) which has the largest trough width.
4. The blank according to one of the preceding claims, characterized in that the crests (24) and troughs (22) have the same shape or at least remain congruent across a shaping region (40) extending from the oral to vestibular direction.
5. The blank according to one of the preceding claims, characterized in that the crests (24), over the course of the dental arch (11), form a ridge line which is inclined towards the plane of occlusion and in particular towards the side of the blank (10) adjacent to the teeth.
6. The dental prosthesis according to claim 5, characterized in that the ridge line, as viewed from the vestibular direction, extends in a straight, curved, S-shaped manner or according to the curve of Spee, and this at least partially, but in particular completely
7. The blank according to one of the preceding claims, characterized in that the crests (24,) as viewed from vestibular and towards oral direction, extend sloping downwards, i.e. approaching the occlusion plane (60), in particular at an angle of 10 to 40 degrees, preferably between 15 and 25 degrees.
8. The blank according to claim 5, characterized in that the blank (10) has a boundary surface (16) which is inclined towards the occlusal plane and has a greater height of the material corresponding to the teeth in the distal direction than in the mesial direction.
9. The blank according to one of the preceding claims, characterized in that a transition region is provided between the region of the molars (26) and the region of the anterior teeth (33), in which the shape of the crests (24) and troughs (22) merges from parallel into radial.
10. The blank according to one of the preceding claims, characterized in that the tooth-colored material (12) of the blank (10) in the blank state has a diameter or a width of more than 5 cm and in particular a flat cylindrical shape having a diameter/height ratio of more than 2 to 1, preferably more than 3 to 1.
11. The blank according to one of the preceding claims, characterized in that an additional layer of a material having different refractive properties, in particular due to different refractive indices of this material as compared to the flesh-colored and the tooth-colored material (14, 12), is arranged between the tooth-colored and the flesh-colored material.
12. The blank according to one of the preceding claims, characterized in that the ribs (24) limiting the premolars or limiting at least the second premolar are formed such that they are formed more pronounced than those ribs (24) limiting the molars or limiting at least the second molar.

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